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Background: Genetic variants associated with cardiomyopathies (CMPs) are prevalent in the general population. In young athletes, CMPs account for roughly a quarter of sudden cardiac death, with further unexplained clustering in specific sports. Consequently, most CMPs form a contraindication for competitive sports. We hypothesized that genetic variants might (paradoxically) improve physical performance early in life while impairing cardiac function later in life. Methods: Systematic PubMed search was done to investigate whether genetic variants in genes associated with CMPs could be related to beneficial performance phenotypes. Summary: In a limited number of studies (n = 6), 2,860 individuals/subjects with genetic variants were able to outperform those without said variants, as measured by running speed (∼38 m/min in heterozygous [HET] mice, n = 6, vs. ∼32 m/min in wild type [WT] mice, n = 7, p = 0.004) and distance (966 ± 169 km HET mice vs. 561 ± 144 km WT mice, p = 0.0035, n = 10), elite athlete status in endurance athletes (n = 1,672, p = 1.43 × 10−8), maximal oxygen uptake in elite athletes (absolute difference not provided, n = 32, p = 0.005), maximal oxygen uptake in unrelated individuals (n = 473, p = 0.0025), personal records in highly trained marathon runners (2:26:28 ± 0:06:23 min HET, n = 32, vs. 2:28:53 ± 0:05:50 min without polymorphism, n = 108, p = 0.020), and peripheral muscle force contraction in patients following a cardiac rehabilitation program (absolute values not provided, n = 260). Key Message: Beneficial effects in genetic variants associated with CMPs could hypothetically play a role in the selection of young athletes, consequently explaining the prevalence of such genetic variants in athletes and the general population. [ABSTRACT FROM AUTHOR]

Background. The hemodynamic cardiac profiler (HCP) is a new, non-invasive, operator-independent screening tool that uses six independent electrode pairs on the frontal thoracic skin, and a low-intensity, patient-safe, high-frequency applied alternating current to measure ventricular volume dynamics during the cardiac cycle for producing ventricular volume-time curves (VTCs). Objective. To validate VTCs from HCP against VTCs from MRI in healthy volunteers. Approach. Left- and right-ventricular VTCs were obtained by HCP and MRI in six healthy participants in supine position. Since HCP is not compatible with MRI, HCP measurements were performed within 20 min before and immediately after MRI, without intermittent fluid intake or release by participants. Intraclass correlation coefficients (ICCs) were calculated to validate HCP-VTC against MRI-VTC and to assess repeatability of HCP measurements before and after MRI. Bland-Altman plots were used to assess agreement between relevant HCP- and MRI-VTC-derived parameters. Precision of HCP's measurement of VTC-derived parameters was determined for each study participant by calculating the coefficients of variation and repeatability coefficients. Main results. Left- and right-ventricular VTC ICCs between HCP and MRI were >0.8 for all study participants, indicating excellent agreement between HCP-VTCs and MRI-VTCs. Mean (range) ICC of HCP right-ventricular VTC versus MRI right-ventricular VTC was 0.94 (0.88-0.99) and seemed to be slightly higher than the mean ICC of HCP left-ventricular VTC versus MRI-VTC (0.91 (0.80-0.96)). The repeatability coefficient for HCP's measurement of systolic time (tSys) was 45.0 ms at a mean value of 282.9 ± 26.3 ms. Repeatability of biventricular HCP-VTCs was excellent (ICC 0.96 (0.907-0.995)). Significance. Ventricular volume dynamics measured by HCP-VTCs show excellent agreement with VTCs measured by MRI. Since abnormal tSys is a sign of numerous cardiac diseases, the HCP may potentially be used as a diagnostic screening tool., (Creative Commons Attribution license.)